This study was carried out to determine the antimicrobial activity of seed oil of Moringa oleifera and garlic against some selected food-borne microorganisms (Staphylococcus aureus, Escherichia coli, Salmonella spp and Pseudomonas aeruginosa) using disc diffusion method. The antibacterial assay results shows that the seed oil of Moringa oleifera was inactive against all the tested organisms, even at 100 % concentration. In contrast, garlic oil was found to be active against all the tested organisms. The highest inhibition was observed in E. coli (12 mm) at 100 % concentration, while at 20 % concentration, Salmonella Sp and P. aeruginosa showed the least inhibiton (6 mm). The results of the phytochemical screening revealed the presence of alkaloid, saponins, and tannins in seed oil of garlic, whereas only saponins were detected in the seed oil of Moringa oleifera. The antimicrobial activity of the seed oil of garlic may be attributed to its phytochemicals components which were not detected in the seed oil of Moringa oleifera. The results of this study have shown the potentials of the seed oil of garlic as an antimicrobial agent more especially in foods, by inhibiting the growth of the test organisms, which range from food-borne pathogens to food spoilage organisms.
TABLE OF CONTENTS
Fly leaf ............................................................................................................... I
Title page ............................................................................................................ II
Declaraion ........................................................................................................... III
Certification ............................................................................................................... IV Acknowledgments ........................................................................................................V
Abstract .............................................................................................................VII
Contents .............................................................................................................VIII
CHAPTER ONE
1.0 Introduction ..................................................................................................... 1
1.1 Aim and Objectives ................................................................................................. 5
1.2 Significance of the Study ................................................................................... 6
1.3 Scope of the Study ............................................................................................ 6
CHAPTER TWO
2.0. Moringa oleifera ............................................................................................. 7
2.1.1 Phytochemistry ............................................................................................. 8
2.1.2 Anti-hypertensive, diuretic and cholesterol lowering activities ......................... 10
2.1.3 Antipasmodic, antiulcer and hepatoprotective activities ....................................11
2.1.4 Antibacterial and antifungal activities ............................................................12
2.1.5 Antitumor and anticancer activities .................................................................12
2.1.6 Other diverse activities of M. oleifera .............................................................13
2.1.7 Moringa seeds as coagulant ...........................................................................14
2.1.8 Microbial elimination with Moringa seeds ......................................................15
2.1.9 Moringa seeds as biosorbent ....................................................................... 16
2.2. GARLIC (Allium sativum L.) ............................................................................ 16
2.2.1. Natural antibiotic effect ............................................................................17
2.2.2. Effect of Garlic against viral infection ........................................................18
2.2.3. Effect of Garlic on fungal infection ............................................................18
2.3 Profile of the Test Organisms ................................................................................. 20
2.3.1 Escherichia coli .................................................................................... 20
2.3.2 Staphylococcus aureus ............................................................................... 21
2.3.3 Pseudomonas aeruginosa ........................................................................... 22
2.3.4 Salmonella Spp ......................................................................................... 23
CHAPTER THREE
3.0 Collection of the plants oil ............................................................................ 25
3.1 Sample processing and biochemical test ....................................................... 25
3.2 Phytochemical Screening ...............................................................................26
3.2.1 Test for Alkaloids (Wagner’s reagent) ..........................................................26
3.2.2 Test for Flavonoids (Alkaline reagent test) ....................................................26
3.2.3 Test for Saponins (Foam test) ......................................................................26
3.2.4 Test for Tannins (Braymer’s test) .................................................................26
3.3 Preparation of Sensitivity Discs ......................................................................27
3.4 Standardization of Inoculum ......................................................................... 27
3.5 Antimicrobial susceptibility test .....................................................................27
CHAPTER FOUR
4.0 Results ......................................................................................................... 29
CHAPTER FIVE
5.0 Discussion ......................................................................................................... 37
5.1 Conclusion .................................................................................................39
5.2 Recommendation ...............................................................................................39